A communication device comprises a processor; and a diplexer comprising a low pass filter passing signals with frequency below a first frequency threshold, the low pass filter having a first input and a first output, and a second filter being one of a high pass filter and a band pass filter passing signals with frequency above a second frequency threshold, the second filter having a second input and a second output; and a switch controllable by the processor for connecting the second input to a termination in a first state and connecting the second input to the first input in a second state responsive to a control signal from the processor, wherein the first output is coupled to the second output and the first input is configured to receive an input signal having a frequency range covering at least the first frequency threshold.